1. Field of the Invention
The present invention relates to a wiper device which wipes a glass surface such as a windshield glass of a vehicle.
2. Description of the Related Art
There has been known, as disclosed in Japanese Utility Model Application Laid-Open (JP-U) No. 63-79256, a wiper arm that is connected to a wiper blade in such a manner as to be disposed at the side of the wiper blade and a connecting member formed at one end portion of the wiper blade and projecting at the side of the wiper blade in the transverse direction of the wiper blade and used to connect the wiper arm with the wiper blade. For this reason, when the wiper blade moves slidingly on a windshield glass surface, deflection of a longitudinal-direction end portion of the wiper blade toward the windshield glass surface around a portion where the wiper arm and the wiper blade are connected is prevented. However, since the wiper device is formed to have the above-described structure, the visual field of an occupant of a vehicle is limited in a wide range.
Further, as another example of a wide device, there has been known, as disclosed in Japanese Utility Model Application Laid-Open (JP-U) No. 2-80054, a pantographic wiper device in which the position of a wiper blade is changed in such a manner that the wiper blade is moved slidingly on a windshield glass surface by using a quadric linking mechanism including a main arm and a sub-arm.
On the other hand, in this type of pantographic wiper device, each end portion of the main arm and the sub-arm is connected to the wiper blade at the central portion of the wiper blade. For this reason, there is a possibility that a leading end and a rear end of the wiper blade deflect toward the windshield glass surface around the portion where each arm is connected to the wiper blade during pivotal movement of the wiper blade due to backlash generated by connection of each arm to the wiper blade, or the like. Moreover, this pantographic wiper device is provided with the sub-arm to maintain the wiping position of the wiper blade, and therefore, the visual field of an occupant of a vehicle is limited in a wide range.